The .308 Winchester has the bullet speed and weight that closely matches the .30-06 at shorter ranges.
Many Elk hunters like the .308 for shots that will be at 200 yards or less. Beyond that, the bullet drop will begin to pose problems.
In the .308 Winchester, a 180-grain bullet will retain over 1,200 ft/lbs of energy at 400 yards but will have dropped some 52 inches.
Consider that you may have a target that is moving and you have a great amount to deal with when taking a shot.
This is why it is important to find out about the type of terrain you will be hunting in.
Do not hesitate to contact the U.S. Forest Service or the Game and Fish department for the state you will be hunting in for additional information.
The .308 Winchester has been a successful elk caliber for many years.